From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751981AbdJCU2V (ORCPT ); Tue, 3 Oct 2017 16:28:21 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:33887 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751820AbdJCU2T (ORCPT ); Tue, 3 Oct 2017 16:28:19 -0400 Subject: Re: [PATCH v9 12/12] mm: stop zeroing memory during allocation in vmemmap From: Pasha Tatashin To: Michal Hocko Cc: linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, kasan-dev@googlegroups.com, borntraeger@de.ibm.com, heiko.carstens@de.ibm.com, davem@davemloft.net, willy@infradead.org, ard.biesheuvel@linaro.org, mark.rutland@arm.com, will.deacon@arm.com, catalin.marinas@arm.com, sam@ravnborg.org, mgorman@techsingularity.net, steven.sistare@oracle.com, daniel.m.jordan@oracle.com, bob.picco@oracle.com References: <20170920201714.19817-1-pasha.tatashin@oracle.com> <20170920201714.19817-13-pasha.tatashin@oracle.com> <20171003131952.aqq377pjug5me6go@dhcp22.suse.cz> Message-ID: Date: Tue, 3 Oct 2017 16:26:51 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Source-IP: userv0021.oracle.com [156.151.31.71] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Michal, I decided not to merge these two patches, because in addition to sparc optimization move, we have this dependancies: mm: zero reserved and unavailable struct pages must be before mm: stop zeroing memory during allocation in vmemmap. Otherwise, we can end-up with struct pages that are not zeroed properly. However, the first patch depends on mm: zero struct pages during initialization As it uses mm_zero_struct_page(). Pasha On 10/03/2017 11:34 AM, Pasha Tatashin wrote: > On 10/03/2017 09:19 AM, Michal Hocko wrote: >> On Wed 20-09-17 16:17:14, Pavel Tatashin wrote: >>> vmemmap_alloc_block() will no longer zero the block, so zero memory >>> at its call sites for everything except struct pages.  Struct page >>> memory >>> is zero'd by struct page initialization. >>> >>> Replace allocators in sprase-vmemmap to use the non-zeroing version. So, >>> we will get the performance improvement by zeroing the memory in >>> parallel >>> when struct pages are zeroed. >> >> Is it possible to merge this patch with >> http://lkml.kernel.org/r/20170920201714.19817-7-pasha.tatashin@oracle.com > > Yes, I will do that. It would also require re-arranging > [PATCH v9 07/12] sparc64: optimized struct page zeroing > optimization to come after this patch. > > Pasha